Placidus and Orb 0 on a Birth Chart: What the Settings Mean

"Placidus, Orb 0" names two separate settings: Placidus is the house system that divides your chart into twelve houses, and "Orb 0" is, in all likelihood, a house-cusp margin switched off, so each planet counts in a house only once it has passed that house's cusp. It is not an aspect orb, and it does not mean your chart has no aspects.

Most people meet this line on a chart image shared by a friend or saved from a free chart site, sitting above the wheel like small print. Many answers online say the 0 is an aspect orb, or that it means your chart has no aspects. The software's own documentation points elsewhere. Here is what every part of the line means, and which settings can actually move a planet.

What does the settings line on a chart mean?

Chart generators often summarise their settings in one header line, something like Tropical, Placidus, Orb: 0, True Node. Read it as a list of separate choices the software made when it drew your chart:

• Tropical is the zodiac. 0° Aries is fixed to the March equinox, so the signs follow the seasons. This is the standard for Western astrology. The alternative, Sidereal, fixes the signs to the stars and currently sits about 24° earlier.
• Placidus is the house system. It decides where each of the twelve houses begins.
• Orb: 0 in the header is most likely a house-cusp orb; next to an aspect, an orb is that aspect's distance from exact.
• True Node (or Mean Node) is which calculation of the Moon's Nodes was used.

None of these is a placement or a trait. They are the frame drawn around your planets, and only a few of them can change which house a planet is in.

What does Placidus mean on your chart?

Placidus means your houses were drawn with the Placidus house system, the default on most chart sites. It divides the sky by time: each quarter of the chart, between two of the four angles, is split into three houses according to the time each degree of the zodiac takes to climb from the horizon to the Midheaven. Houses come out unequal in size, and your Ascendant and Midheaven are always the 1st and 10th house cusps.

The house system is the setting that matters most for your houses, because it decides where every boundary falls. A planet close to a cusp may sit in your 6th house in Placidus and your 7th in another system. Our guide to Placidus and other house systems covers how each method works, and Whole Sign vs Placidus houses shows which planets shift between the two most popular ones.

What does "Orb: 0" mean in the chart header?

"Orb: 0" in the header beside "Placidus" is best read as a house-cusp orb. The software behind the free generators that print this line has a house-orb setting that counts a planet as already being in the next house when it sits within a set number of degrees before that house's cusp; the developer's documentation describes it this way, separately from the aspect settings. The chart itself does not label the header, so this is the reading the documentation supports rather than one printed on the page.

At 0, that option is off. A planet belongs to a house only once it has actually passed the cusp, which is the ordinary rule every astrologer learns first. Other chart programs offer the same idea under names like "house cusp margin", usually with a default of a few degrees.

Context decides which orb you are looking at. On chart sites where "orb" appears with the aspect settings, such as a line reading "Placidus houses, orbs 10°", it means aspect orbs. When it sits alone in the header above the house-cusp table, as in "Placidus Orb: 0", the house-cusp setting is the reading that fits.

An example makes it concrete. Say your Placidus 10th-house cusp is at 15° Capricorn and your Saturn is at 13° Capricorn, two degrees before it.

• Orb 0: Saturn is in the 9th house, because it has not reached the cusp.
• House-cusp orb of 3°: Saturn is within 3° of the 10th cusp, so the chart counts it in the 10th house.

Some astrologers like that margin, because a planet sitting right on a cusp often behaves like part of the next house. Most free charts leave it at 0 and let you make the call yourself.

What is an aspect orb?

An aspect orb is the distance, in degrees, between an aspect's exact angle and the actual angle between two planets. Aspects are set angles: 0° for a conjunction, 60° for a sextile, 90° for a square, 120° for a trine and 180° for an opposition. Planets rarely sit at exactly those angles, so astrologers allow some leeway.

Say Venus is at 12° Leo and Mars is at 16° Aquarius. The two planets are 184° apart: an opposition with a 4° orb. If the allowance for oppositions is 8°, the aspect counts. If Mars were at 25° Aquarius, 13° from exact, it would not.

The tighter the orb, the louder the aspect. A Moon–Saturn square at 1° tends to shape how someone handles feelings every day; the same square at 7° is more of a background note. Our guide to aspects explains what each angle means in a life.

Orb 0 next to a single aspect

In an aspect list or grid, an orb of 0, or 0°00′, means that aspect is exact or very nearly so. When the software shows whole degrees, 0 means the two planets are less than a degree from the exact angle. Astrologers call these partile aspects, and they are the first ones worth reading. If your Sun and Moon show a trine with orb 0, the harmony between what you want and what you need is one of the clearest signatures you have.

What are typical aspect orbs?

Typical modern orbs are about 8° to 10° for conjunctions and oppositions, 6° to 8° for squares and trines, and 4° to 6° for sextiles, with the Sun and Moon often allowed a little more. Minor aspects, such as the quincunx at 150°, usually get 2° to 3°.

Traditions handle orbs differently. Medieval and Renaissance astrologers gave orbs to the planets rather than to the aspects, with the Sun and Moon receiving the widest, and two planets were in aspect when they came within half of their two orbs added together. Most modern software assigns orbs by aspect type instead. Popular chart sites differ by a few degrees, which is one reason two sites can list slightly different aspects for the same chart.

The orbs Celestio uses

Celestio reads the five major aspects with these orbs:

• Conjunction and opposition: 8°
• Square and trine: 7°
• Sextile: 5°
• Sun or Moon involved: 2° wider, so a Sun–Moon square counts up to 9°
• Lunar Nodes and Chiron: 3°

These sit in the middle of the usual range: wide enough to catch the aspects you will feel, tight enough that each one earns its place in your reading.

Which settings change your houses?

Three settings can move a planet into a different house: the house system, a house-cusp orb and, in Whole Sign houses only, the zodiac. The rest change something else.

1. House system: redraws every boundary, so planets near a cusp can change house.
2. House-cusp orb: moves a planet just before a cusp into the next house.
3. Aspect orbs: change which aspects are listed, never houses.
4. True or Mean Node: changes only the Nodes' own position. The Mean Node is a smoothed average that always moves backward; the True Node follows the Moon's real wobble and sometimes turns direct. They usually sit within a degree or two of each other, which matters only when a Node is near the edge of a sign or a house.
5. Tropical or Sidereal: shifts every position by about 24°, so many planets change sign. In Placidus it never changes a house, because planets and cusps shift together. In Whole Sign it can, because the sign boundaries that define each house move under the planets.

Celestio uses the tropical zodiac and Placidus houses. For births beyond the polar circles, where Placidus cannot be calculated, it uses Whole Sign houses, and your chart shows which system was used.

How do you read orbs in your own chart?

Read your aspects from tightest to widest, because the tight ones describe the patterns people notice in you first.

1. Find your aspect list and sort it by orb, smallest first.
2. Read aspects under 2° as core themes, the ones that show up in most areas of life.
3. Read aspects of 2° to 5° as strong, regular patterns.
4. Read wider aspects as background tones that colour the rest.
5. Notice when a tight aspect involves your Sun, Moon or chart ruler; those carry the most weight.

Then look at any planet within two or three degrees of a house cusp and read it with a little of both houses. Our step-by-step guide to reading your birth chart puts both habits alongside signs and houses.

Frequently asked questions

Does Orb 0 mean my chart has no aspects?

No. "Orb: 0" in a chart's header line does not mean your chart has no aspects. On the generators that print it beside "Placidus", the software's documentation points to a house-cusp setting that is switched off, so planets count in a house only after passing its cusp. Your aspects are listed separately, with their own orbs, usually in a grid or table below the wheel.

Does the house system change my aspects?

No. A house system never changes your aspects, because aspects are measured between the planets themselves in degrees of the zodiac. They are identical in Placidus, Whole Sign or any other system. Changing the house system only moves the house lines. Changing the aspect orbs is what changes which aspects appear: wider orbs include more, tighter orbs fewer.

Is an aspect with a 0° orb stronger?

Yes. An aspect with a 0° orb, within a degree of exact, is one of the most pronounced themes in a chart. Astrologers call these partile aspects, and they tend to describe something that shows up early and stays: a Mercury–Mars conjunction at 0° might look like someone who speaks the instant they have a thought, in every room they enter.

Should I use True Node or Mean Node?

True Node and Mean Node are both valid, and astrologers are split between them. The Mean Node is a smoothed average that always moves backward; the True Node tracks the Moon's actual orbit and occasionally turns direct. They rarely differ by more than a degree or two, so the choice matters only when a Node sits near a sign or house boundary. Our guide to the lunar Nodes explains what they mean.

What orb should I use for my birth chart?

Standard modern orbs work well for a birth chart: about 8° for conjunctions and oppositions, 7° for squares and trines and 5° for sextiles, with a little extra for the Sun and Moon. These are close to what most astrologers and chart sites use. Then give the tightest aspects the most weight, since orb size tells you which conversations in your chart are loudest.

See your own settings in action

The settings line makes sense fastest when you watch it work on your own placements. Your free birth chart on Celestio shows which house system was used, reads the five major aspects at the orbs above, and comes with a reading written for that exact chart, so the small print becomes the frame around your own planets.